Many mobile devices are configured to utilize Universal Integrated Circuit Cards (UICCs) that enable the mobile devices to access services provided by Mobile Network Operators (MNOs). In particular, each UICC includes at least a microprocessor and a read-only memory (ROM), where the ROM is configured to store an MNO profile—also referred to herein as a Subscriber Identity Module (SIM)—that a mobile device can utilize to register and interact with an MNO. Typically, a UICC takes the form of a small removable card (commonly referred to as a SIM card) that is configured to be inserted into a UICC-receiving bay included in a mobile device. In more recent implementations, however, UICCs are being embedded directly into system boards of mobile devices. These electronic/embedded UICCs (eUICCs) can provide advantages over traditional SIM cards, e.g., an eUICC can store a number of MNO profiles—referred to herein as electronic Subscriber Identity Modules (eSIMs)—and can eliminate the need to include UICC-receiving bays in mobile devices.
Despite the various advantages provided by eUICCs, particular issues are arising that have yet to be addressed. For example, in traditional approaches, SIM vendors can purchase eUICCs from chip manufacturers and load sensitive information (e.g., bootstrap eSIMs for establishing preliminary connections to MNOs) onto the eUICCs prior to distribution. However, the ever-decreasing scale of eUICCs is imposing new limitations on the ability for the SIM vendors to load sensitive information onto the eUICCs. For example, wafer-level chip scale packaging (WLCSP)—a process that yields smaller chip sizes—can require sensitive information to be loaded onto the chips when they are manufactured. Consequently, SIM vendors are required to share sensitive information with the chip manufacturers, which is undesirable for a variety of reasons and introduces security issues. Consequently, there exists a need for a technique where current chip manufacturing techniques can be utilized without requiring sensitive information to be shared between SIM vendors and chip manufacturers.